分岔隧道中夹岩柱围岩应力及最小厚度研究
Research on surrounding rock pressure and minimum thickness of middle rocky column in the branched tunnel

为揭示分岔隧道中夹岩柱围岩压力及最小厚度,基于分岔隧道小净距段平衡拱的2种极限情况,结合普氏理论,推导分岔隧道中夹岩柱的围岩压力表达式;并针对壁板坡分岔隧道小净距段,运用FLAC3D对不同厚度的中夹岩柱进行数值模拟。研究结果表明:当中夹岩柱仅采取普通锚喷支护时,中夹岩柱的最小厚度应控制在8 m以上,若想减小中夹岩柱厚度,则需对其进行加固处理。为确定分岔隧道中夹岩柱围岩压力及最小厚度提供了理论基础。
This paper reveded reveal the surrounding rock pressure and minimum thickness of middle rocky column in the branched tunnel. Based on two limit cases of the balanced arch in the forked tunnel small clear distance zone, the expression of surrounding rock pressure of middle rocky column in the forked tunnel were deduced by Protodyakonov''''s theory. According to the small clear distance zone in forked tunnel, the numerical simulation of the middle rocky column in relation to different thickness were carried out. The results show that: when the middle rocky column is only taken ordinary bolting and shotcrete lining, the minimum thickness of the middle rocky column should be controlled in more than 8 m. More reinforcement should be applied to reduce the thickness of middle rocky column. It can provide a theoretical basis for determining the rock pressure and minimum thickness of the middle rocky column in forked tunnel